Blood Flashcards
What are the physiological functions of blood?
Transportation medium:
- Blood gases
- Nutrients
- Metabolites
- Information
- Heat
- Defense mechanism
- Haemostasis
- Homeostasis
Give the total buffer capacity for a bicarbonate buffer
53%
Give the total buffer capacity for non bicarbonate buffer
47%
Haemostasis
Coagulation
Reactions after vessel injuries
Effect of blood on homeostasis
Promotes:
- Isovolemia
- Isotonia
- Isoionia
- Isohydria
What proportion of blood is water?
90%
Composition of blood
- Plasma
- RBCs
- WBCs
- Thrombocytes
Blood + Anticoagulation and Centrifugation →
Plasma (with fibrinogen) + Cellular elements
Blood + long resting period
Serum (no fibrinogen)
Blood clot (fibrin-web)
Hematocrit
- Diagnostic parameter
- Shows the proportion of corpuscular elements to the whole volume
Average hematocrit value
40% or 0.4
Average hematocrit value for dogs
0.46
Average hematocrit value for hens
0.32
What does the hematocrit show us?
The veloicty of sedimentation corpuscular elements
Blood cell sedimentation rate for horses
60-70 mm/hour
Blood cell sedimentation rate for dogs
5-10 mm/hour
Blood cell sedimentation rate for swine
1-14 mm/hour
Blood cell sedimentation rate for hens
1-4 mm/hour
Blood cell sedimentation rate for ruminants
0-2 mm/hour
Blood cell sedimentation rate for human
3-10 mm/hour
pH of blood
7.35 - 7.45
pHvenous <pHarterial
Give the relative viscosity of:
- Total blood
- Plasma
- Water
- Total blood: 4 (max 5.6)
- Plasma: 2
- Water: 1
Give the density of plasma
1020 g/l
Give the density of total blood
1052 g/l
Give the density of blood cells
1090 g/l
Give the freezing point of blood
-0.56°C
Give the total osmotic pressure of blood
700 kPa
Give the colloidosmotic/oncotic pressure of blood
2.7-4kPa
Give the osmolarity of blood
300 mmol/l
Give the blood volume of the body
80 ml/bwt
Give the plasma volume of the body
45 ml/bwkg
Give the blood cell volume of the body
35 ml/bwkg
Formula to calculate blood volume
V = Vrbc / 0.9 x Ht
V = Vp / (1-0.9 x Ht)
- Vp = Plasma volume*
- Vrbc = blood cell volume*
- Ht = Hematocrit value*
1, 4 and 7 are examples of…
Normocythaemia
2, 5 and 8 are examples of
Polycythaemia
3, 6 and 9 are examples of…
Olygocythaemia
Normocythaemic normovolaemia
Healthy blood volume
Polycythaemic normovolaemia
- Haemoconcentration
- Viscosity increases
- Increased load on heart
Olygocythaemic normovolaemia
- Haemodilution
- Blood gets diluted with concurrent normal volume
Normocythaemic hypovolaemia (Oligaemia)
- Blood cells and plasma loss together
- Blood loss
- Plasma replaced quickly
- Cells return slowly
Polycythaemic hypovolaemia
- Anhydraemia: Lack of water/thirst
- Haemoconcentration
Normocythaemic hypervolaemia
- Plethora (A large amount)
- Excess transfusion
- Permanent, exhausting physical work
Olygocythaemic hypervolaemia
- Hydraemia
- Intake of excess water
- Infusion (followed by haemodilution)
Factors affecting blood volume
- Body fat
- Body position
- Muscle work
- Climate
- Nutrition
- Age
- Pregnancy
- Changes in water supply
Give the size of blood cells in:
- Mammals
- Birds
- Mammals: 6x2 µm
- Birds: 12x7 µm
Mean number of RBCs in the body
5 x 1012/L
Mitochondria are not present in RBCs, true or false
True
Average lifetime of RBCs
Average: 120 days
Cattle, swine: 60 days
Birds: 30 days
Haemoglobin concentration of blood
- 120-180 g/l
- 1.5-2.5 mmol/l
Haemoglobin content in 1g of RBCs
0.35g
35% haemoglobin concentraion
MCHC
Mean corpuscular hemoglobin concentration
Approx 5mmol/l
Calculate MCHC
Hb/Ht
- Hb = Hemaglobin*
- Ht = Hematocrit*
MCH
Value
Mean corpsucular hemoglobin
0.45 fmol/pc
Calculate MCH
Hb/RBC
MCV
Mean corpuscular volume
80-100 femtoliter/pc
Calculate MCV
Ht/RBC
Hemolysis
Leakage or disruption of the blood cells
Can be:
- Hypoosmosis
- Hyperosmosis
Hypoosmosis
- Blood cells placed in hypotonic solution
- Water flows into cells
- Cells swell and disrupt
Hyperosmosis
- Blood dropped into hypertonic solution
- Water leaves the cells
- Cells shrink
Osmotic resistance
RBCs adapt and are therefore resistant to the significant changes of osmotic circumstances
Give the minimal osmotic resistance of RBCs
70-120 mmol/l NaCl
haemolysis just starts
Give the maximum osmotic resistance of RBCs
50 - 90 mmol/l NaCl
all the cells haemolyse
Osmotic resistance of the RBC is attributed to…
- The characteristics of the RBC membrane
- Spectrin protein molecules
- Fixed in place by ankyrine
- Give a flexible feature ‘molecular springs’
- On the internal side of the membrane
- Spectrin protein molecules
Which physical effects can cause membrane haemolysis?
- Freezing
- Dissolving
- Shaking
- Shocking
- Osmosis
Which chemical effects can cause membrane haemolysis?
- Acids
- Liposolvents (E.g Ether, Chloroform)
- Surface tension reducers (Bile salts)
Which toxins can cause membrane haemolysis?
- Bacterial toxins
- Snake toxins
- Plant toxins
Haemoglobin
- Pigment (protein)
- Colours the RBCs
- Transports blood gases
- Forms the blood’s buffer capacity
Give the molecular weight of Haemoglobin
65,000 Da
- 4 sub units*
- 120-180 g/lblood = 1.5 - 2.5 mmol/l*
Haem/Hem
- Ferro-protoporphyrine
- Porphyrine base with 4 coordination sites
- Only the bivalent iron atom can bind to oxygen reversibly
- (Oxygenation)
Methaemoglobin
- Oxygenated derivative
- Binds to oxygen irreversibly
- Returned to the haemoglobin in the:
- Methaemoglobin-reductase-NADPH-systen
Fe2+ prefixes
- HEM
- Ferro-
- Hemo-
Fe3+ prefixes
- Hemin
- Ferri-
- Hemi-
Globin
- Determines characteristics of oxygen binding
- Allows allosteric stimulation
- Binds to oxygen stronger after accepting the former one
Describe the evolution of blood cell genetics
- Originally one genetic chain (until 500 million years ago)
- Became alpha and beta chains
- 120 million years ago, beta chain spit into gamma1 and gamma2
- Beta1, beta2 and the epsylong chains also appeared through mutation
Sickle-cell anaemia
- Single amino acid change
- The 6th position of the beta chain should contain alanine
- It contains glutamine instead
Give the known Asian vector of malaria
Iwi bird
The age effect on RBCs
- Hb-F has a smaller affinity to 2,3-DPG
- (From cell metabolism, allows oxygen transport from mother to fetus)
- When compared with Hb-A due to the amino acid sequence
Adult haemoglobin
Hb-A = 2 alpha chains + 2 beta chains
Foetal haemoglobin
Hb-F = 2 alpha chains + 2 gamma chains
Oxygen in RBCs
- Bind to Fe2+ (reversible)
- 1 haem binds to 1 O2
- 1.34mlO2/ Hb
- 160mlO2/l blood
- 16% Volume
Carbon dioxide in RBCs
- Carbamino-hemoglobin
- Responsible for 20% CO2 transport
- Hb-NH2 + CO2 → Hb-N-COOH
Peak absorbance wavelengths for:
- HbO2
- Hb
- HbO2: 540nm, 580nm
- Hb: 555nm
Haemoglobin composition: Fe2+
Deoxi-Hb
Haemoglobin composition: Fe2+ O2
Oxygenated-Hb
Haemoglobin composition: Fe2+ CO
CO-Hb
Haemoglobin composition: Fe3+
Hemiglobin (Methaemoglobin)
Haemoglobin composition: Fe3+ Cl
Hemin chloride
Compare the affinity of carbon monoxide to oxygen
Carbon monoxide has 200 times greater affinity than oxygen
Haemoglobin can be irreversibly oxidised by…
OH and Cl radicals
Haemoglobin can reversibly bind to…
Oxygen
Methaemoglobin/Hemiglobin can be reversed by which reducing agent?
Intravenous methylene blue injection
Give the two most important buffer bases in the blood
- Hb-
- HCO3-
Which acid-base pair ensures buffer action in the blood?
HHb/Hb-
What percentage of buffer capacity is provided by haemoglobin?
35%
Which is a better proton acceptor?
- Deoxygenated Hb
- Oxygenated Hb
Deoxygenated
Give the stages of the degradation of haemoglobin
(Not via phagocytosis)
- RBCs → sphaerocytes
- Sphaerocytes → Spleen + liver
- Spleen + Liver release Haemoglobin
- Haptoglobin binds haemoglobin in blood
- Haemopexin binds haemoglobin in plasma
Describe how phagocytes break down haemoglobin
Haemoglobin broken down into:
- Globin → Aminoacid (recirculated)
- HEM → Fe (recirculated)**
- HEM → protoporfirin-IX → Bilirubin (then enters blood)
Name given to bilirubin when bound to Albumin
Bilirubin-I
What percentage of bilirubin-I is conjugated with Glucuronic acid?
80%
What percentage of bilirubin-I is conjugated with sulphate
20%
When bilirubin conjugates, it becomes…
Bilirubin-II
Where is Bilirubin-II deconjugated and how?
- In the gut
- Deconjugated by bacteria
Function of gut bacteria:
- Bilirubin-II →
- Bilirubin-I →
- Stercobilnogen
- Urobilinogen (UBG)
Give the fate of Stercobilnogen
- Oxidised
- Stercobilin formed
- This passes into the faeces (stercobilin makes it brown)
Give the fate of urobilinogen
- Absorbed by the gut
- Portal circulation → Liver (14%)
- (Converted back to bilirubin)
- Absorbed by vv. hemorriodhales (1%)
- Systemic circulation → Renal excretion (Urine)
Bilirubin-II
Bile
Containing bilirubin-II
Bilirubin-I
after degredation by bacteria
Stercobilinogen
Stercobilin
Urobilinogen (UBG)
Urobilinogen (UBG)
In embryonic stages, the red marrow recieves its blood-forming function by…
The embryionic liver
(blood-forming function also given to the spleen in mice)
Blood cell types are derived from
Progenitor cells (after a maturation stage)
During embryonic stages, which primordial cell type doesn’t roam to the bone marrow?
T-progenitor cell
(settles in the thymus, produces T-lymphocyte)
Give the stages of blood cell development
- Omnipotent primordial cell
- Committed progenitor cell
- Burst forming cell, erythroid
- CFC-E colony
- Normoblasts
- Reticulocyte
- Erythrocyte
What can a reticulocyte number >0.5% be a clinical indicator of?
Forced blood synthesis
Describe nucleus expulsion during blood cell development
- MHC structures roam to the pole
- Nucleus and MHC structures are exocytosed
- Blood type-specific antigens remain on the RBC surface
- Reticulocyte forms inside (not fully mature RBC yet)
Hb-mRNA is left in the cell, haemoglobin synthesis continues in endoplasmic reticulum
Give the factors affecting RBC synthesis
- Oxygen supply
- Hypoxia
- High altitude
- Blood loss
- Kidney status
- REF (renal erythropoietic factor)
- Age
Describe the spleen colony test
- X-rays halt hematopoesis in animal 1
- Bone marrow cells implanted from animal 2 to animal 1
- 2 weeks lapse, implanted RBCs appear in animal 1
- Spleen becomes enlarged, signal peptides increase in blood
Erythropoetin
- Size (in mouse)
- Producing cell
- Target Cell
- Size: 51,000 Da
- Producing cell: Kidney cells
- Target cell: CFU
(RBCs)
Interleukin-3 (IL-3)
- Size (in mouse)
- Producing cell
- Target Cell
- Size: 25,000 Da
- Producing cell: T-lymphocyte, epidermis
- Target Cell: CFU, progenitor and mature cells
Granulocyte/Macrophage SF (GM-SF)
- Size (in mouse)
- Producing cell
- Target Cell
- Size: 23,000
- Producing cell: T-lymphocyte, endothel, fibroblast
- Target cell: GM progenitor cells
Granulocyte CSF (G-CSF)
- Size (in mouse)
- Producing cell
- Target Cell
- Size: 25,000 Da
- Producing cell: Macrophage, fibroblast
- Target cell: GM progenitor and neutrophil
Macrophage CSF (M-CSF)
- Size (in mouse)
- Producing cell
- Target Cell
- Size: 70,000 Da
- Producing cell: Fibroblast, macrophage, endothel
- Target cell: GM progenitor and Macrophage
Steel factor
- Size (in mouse)
- Producing cell
- Target Cell
- Size: 40-50,000 Da
- Producing cell: Stroma of many organs
- Target cell: CFU
(RBCs)